Background Few sources regularly monitor hospitalizations associated with viral gastroenteritis. This study provides current hospitalization trends associated with two common viruses causing gastroenteritis: norovirus and rotavirus.

Objective This study aims to supplement the surveillance data provided by the CDC by describing latest trends (through April 30, 2024) overall and for each virus. This study also provides valuable insight into two at-risk populations: infants and children (age 0-4) and older adults (age 65 and over).

Methods Using a subset of real-world electronic health record (EHR) data from Truveta, a growing collective of health systems that provides more than 18% of all daily clinical care in the US, we identified people who were hospitalized between October 01, 2019 and April 30, 2024. We identified people who tested positive for each virus within 14 days of the hospitalization. We report monthly trends in the rate of hospitalizations associated with each virus per all hospitalizations and test positivity for the overall population and the two high-risk sub populations: infants and children and older adults.

Results We included 5,533 hospitalizations of 5,424 unique patients who tested positive for a monitored virus between October 01, 2019 and April 30, 2024.

Additionally, we included 238,344 lab results across 113,219 unique patients of which 10,811 were positive between October 01, 2019 and April 30, 2024.

Hospitalizations associated with these norovirus and rotavirus accounted for 0.21% of all hospitalizations in April 2024 (+5.4% from March 2024). The combined test positivity rate of these two enteric viruses was 8.4% in April 2024. For the population between age 0-4 years old, the hospitalizations associated with these two enteric viruses accounted for 0.13% of all hospitalizations in April (+11.5% from March 2024). The enteric virus test positivity rate was 18.4% for the month of April in this age group. In the population over 65 years of age, hospitalizations associated with these enteric viruses accounted for 0.22% of all hospitalizations in April 2024 (-4.8% from March 2024). The enteric virus test positivity rate was 6.0% for the month of April in this age group.

Discussion We see evidence that we are in the peak of the norovirus and rotavirus season. The overall timeseries trends of hospitalizations associated with these viruses show a steady increase over the last months, leading to a rate of 0.21% in April 2024 in the overall population. Similar trends can be observed in test positivity rates and the two high-risk sub populations: infants and children and older adults.

In the overall and adult over age 65 population, norovirus causes 2 to 3 times higher hospitalization rates than rotavirus. However, in the population of infants and children, both viruses have similar hospitalization rates. We will continue to monitor trends of norovirus- and rotavirus-associated hospitalizations and their test positivity.

All authors are employees of Truveta, Inc

This study did not receive any funding.

I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.

Yes

The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

Normalized electronic health record data are de-identified by expert determination under the HIPAA Privacy Rule before being made available to researchers. In accordance with 45 C.F.R. Paragraph 46.101 Protection of Human Subjects, our study did not require Institutional Review Board approval because it used only deidentified medical records. All data used in this study are publicly available to Truveta subscribers and may be accessed at studio.truveta.com.

I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals.

Yes

I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).

Yes

I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable.

Yes

The data used in this study are available to all Truveta subscribers and may be accessed at studio.truveta.com